SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9caa851285c05f27c094d85c2921b13eab7fceaf5ba8210d2494639447230b59' 
  AND token = '9aKZG1vf6ymcCmmeynID5SNun0zLExuGACQwDS5HFHg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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