SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2cf892b880cef9c2f90facb51144feab7187aa08442d3135f622b9065c8423b' 
  AND token = 's1mpeqBJLOp/wF5dpQNohysKJ8GymaPshZMNY2rgjxI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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