SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbe9176bd98a4d8fd71707e232b3e813ef5484a7f61f5d72144f621b0a221025' 
  AND token = '6M/IZHSVnVleH2IWN2K/womw4lIPTwH+me44Ot4MHm4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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