SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfcee643ac1c6e999e63b673b7d779829be9dab6ce2c09e61bcfbf57aec691d3' 
  AND token = 'bTtjwBhReXSJ+GKcmdk+P7KVND3PBhAqzO+slyAH4oQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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