SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfd20cdf5123b6e2e4969165f282d96728e48edab460dfebfd89258f60ab2dcd' 
  AND token = 'MZcuVqAQC5cAHWLCnWIPmfKvLTxDi8GiYLXyhPE8rEY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}