SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b53dd79e4ec157c78d701227daeba62e02165f6386ad224fe347c91ce7a84ac' 
  AND token = 'h9lU/dU3bBOteqVr3JW0e/893uARwND/Vr0AcJmczjM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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