SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3eef3c4868d58cc5606b80d90a2889c08373bfa3b12df9f405269dfc850c554' 
  AND token = 'VUiNWKVMhu6ofntXhz1OxkzInyZstJDh96rAIZXvjCg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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