SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8db3e3df9fd0324232c8919097ac0d98590b0b6dc5c35402a836340488c1d47' 
  AND token = 'cYq6rNSIB686wbK/1vAm2SFM2j+DVGVF3EVtNgO+CGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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