SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8cf3addc3cde3ff959e1aa21d61a00e1787c4c0456ac0c5c00078c04a90e59a' 
  AND token = 'fRgkzI9jJpAST1IRy2DdB++GbLkNWYp4pPD+JngKo88=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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