SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94076eec5248a60544be2393162b3164cba71b31c0fee0f8f6edd8233c8d800b' 
  AND token = 'ua1WeX7Cx6K5Fe7UCSzQiVblaw3Y/vanRejmTcx2Pso=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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