SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '074c39e933f46968d5b2da853a348127a847d5743ec0bd1bfc130961894d139e' 
  AND token = 'OJdASvjDI1mk6jVjF1qs3hdgZ5xjrtGzvJczDw5Ug9k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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