SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '476b545276f900131b78596242bfbb8020f5530ce63b8fc9372d3dd894274a2e' 
  AND token = 'C1u2qsRt8cKouy7NWcjTXUUBWjwNlRZYgUpf0jZzuy8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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