SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aea77fcb056a09c3eb12767cdbd2c05faa93dc7725f161eea5cab484766d38e0' 
  AND token = 'ZRYRrIFP73BYVMv3oHLdt8iUjDSjMgyt39yaRu1aoWg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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