SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62f542c45a6533638262541536ddc1b5979e073a83684dc2523db67162a52980' 
  AND token = 'nk5aaQS4QBAxO4D1z58hTymD2y9Tzvtin64NSmEp+nw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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