SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b1a0b5b5facbee65ce60d389f8abcd98b1ce46f910ca102fdf22c112f973a00' 
  AND token = 'bcTNzlpexNEKPZ+BwwbBBcx9yWOXkLy21exYEUqa3nY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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