SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '716ac95a76843aab037b877493e49b90662dd5edb1de4f0e002d916c78db401d' 
  AND token = '9BZtoxQ3DaWnzTY8vUmG96lJ/dRK8vZnHbb51gKDODw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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