SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c102e00e20620df33982a0a5051eb99fd88a7a8f7d41f7f3c4ecf16fc3f88b1b' 
  AND token = '1DLP+05yYHClYVbabtOHRp0hWRqk+NKMXrYg/RGCwBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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