SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '758a49e851150767c3d2f783cf0158312b178eb92309031e556ea4bead668731' 
  AND token = 'I7pfl60ouktMQbU4ZM1Cx+SV1hvkRxw8Lnhd9R3/yR8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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