SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '498b0351e8908b4cff15aaebff625c7ed8c4d988749aca5f34dabc48dfa1c4c0' 
  AND token = 'IsAXaDk5hg8EXeTnXItMmop2CKUaRFhlclQlmkLuo24=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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