SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fcd02ce2de2e610cfaac0a3389cb8089fe207bffec7ce1cd7a3c5f9b1e15908' 
  AND token = 'RBssY1yyCZ2WI+78Ucc7iRs5nZ6f3zmoFOKE2pR4Mv0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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