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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc2489e052979d39496d7d0dc09b134abb4b1feda3ea5f2e75d10a7cc95d5dd2' 
  AND token = 'S+p0ixM4aj0GTTGT9NyZe8JanTqvvYWKT0hqkHdoAV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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