SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04f55918aacbdde571c503868d09b80930a2766ff36c3d1f97b6f65502f7f371' 
  AND token = 'oDyqBASal8YA5IaBsVWnh8yL9NsY6dTvUuyDtdXCUOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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