SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'df3be03c3d9d74641b0d1932a31bb4f548f41b5d992300d13ff0d8482f7c1d16' 
  AND token = 'L2y8UI+2MTl3VCJ74Eil2MZm+qsDtGR2GQRaiAKXfRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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