SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3d724c686d786d9af03e475f74979159e69c1845556bcf42d4a120695a55f01e' 
  AND token = 'cbQCsvTDv7IK6CBkJ1Sghmu+fgey6sS86Ng/BqrTqwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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