SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fef377d14702217beca91b1e45d9f548fe0cc0a3c7d98f2f96867f7e730f12fd' 
  AND token = '0dlO+FiIPCNcdaK/ZpzFO6T+kor7PBSADgzH2nzajcI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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