SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '577593f58350795df844865af5bd3ffa25c6b86fdcb67f7992ee6dee40fe6b1e' 
  AND token = 'F3AcvxjqTreqOnSwpBLbQNdWGm2baHl/KZnqMmvjGRo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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