SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f0c50e947ae6d54547554da17e779b19f626f1769d1d9d01f5671fd996c2b863' 
  AND token = 'pqbeoT2et+t/YiW/10YfenOrKxyFQR8o7EteghQJwFY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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