SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f237c0e3c1d0f37800da17a2e8c74d824758ddc607c745a80471e4351f3cbb01' 
  AND token = 'nL+x7XSLdGJchVV6urI/5Vg2fOV0O5UfhQkm4DFERGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}