SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '46737f81c6f95f97c18e57e2bce664b374c7835e0c133a98def8448bfd008e82' 
  AND token = 'qqbpJE5+6sRrp2DB+fsJgcobYdmJZuSIBca+0z/EpkM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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