SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34bc432622bb3686066dd8c5970101d4d3f0de4aeae3cbd66f2e0984e32778d8' 
  AND token = 'G2TiOvxzwCGzLKpM7MyIExLzwYqVeU/oca0vrD/8Fwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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