SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '227f39ade951b752d9ee5471a7c1ca99bb2671e9e5840efe17688227489c2f10' 
  AND token = 'egX5LLNERjrGv955nVkI6/QBUIGryFhMEx2ZIZTdsKs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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