SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa64d1a956e78ce4f09cb0d708b69167e09bba4ce45c409356b3cb20f4487915' 
  AND token = 'p61RdqJLwHsQ6SI5c8IRhCAqVuZmlO8LnfVrhSuUBBg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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