SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2742dfeaf650524ee7e2fb74652f5d7a12500722f9439b0b4c78e68439449410' 
  AND token = 'NPv+LPbJesTnf4JlF6Lp0X9LDx/tIVpoVbYUZEdHfBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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