SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59feecea840808f027cf623b2e5fe521daa23387e75a158b274160860112ea48' 
  AND token = 'TDzSYjTz5VB2i4eoQM/BbfX/EGCDLsCysabOD20pYN4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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