SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3229b36ea5a8ecf9a67dd7754175a2d0ba7e20b96f5dfe13bf1527688b3fb2d5' 
  AND token = 'QBrjpZl2TWEglZGT87INwNVV5imhwVAzyPW5q7Xu/MI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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