SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0bad15b4a34e45d552e43981a0e71b80cc48314f927e1d332c0d5471170a6522' 
  AND token = 'FZjh5+0MK/rK7rqq0ci/nzLZnr4AsnUVpSugRmKL8vY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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