SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '964bfd88f05ab1e9d5dc4e4d9d4c6d4578a2dafb5bb22ee596105013b9b14edd' 
  AND token = 'PL2GB8HjyZ9AtFyvB+VikwcsWy9UA3g0ATLuzXXflV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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