SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5791eef2f2e276478dc55f8614f3ee58c2b66bc29b1648d500586d4f4df66c1a' 
  AND token = 'oDg1Zl50KDXogLys0S/f03vnCr8PgI+z6ElD+jZEVpw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}