SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '51f5522b0f6686bf2034ff7de276cc0205be16ae980b09995703ad9f60b84507' 
  AND token = 'Teg/6YNrhsm8QGNQuAJfIYwfSZOe0cfpZXZW0Gnm3Lc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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