SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a12e21344651083f2c1052f332b05f9905a4d289ab6135aa0be628edb4b0ab77' 
  AND token = 'kppr+cU4dlfqL7d7cRjl+8Aw+k0X+bSyBH9UKECtR7o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00105

JSON explain

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