SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66c19448243cb79f1467bd36c9206d796956ecea196cbc2746a30436112ade0a' 
  AND token = 'oiycbdAPKYHEEECQfOB4MJXpwYLZlxaZ+uP364UO2lw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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