SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc4e4a2027f3fdce64726705f40bd26b8120a2d8529ce7557bd95b28ac30d87d' 
  AND token = 'ptdkkK6AxsLVZUicOH6PTJYPSvbzxLBMjXGVmJqk8/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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