SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '28dbcecfd88a285650326884559d936698b66711ee1c3d72cac933fbde0d5f0c' 
  AND token = 'e1n27UGxzWkR08DA5kzkDtp5OAEvPXTJSSO2iSBWqr0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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