SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c0824adc506fbcb1de7d1c73ad236046c16843be2e46bba93844bbb82009bdb' 
  AND token = 'FS06ekfJ95VN9dV/ZrCDER0XXo/WkuMwmal446LQCxQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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