SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '76ac3f22e4bb91df4257d4f4e2e04349188b4ae8ac49152edb23976409ce7121' 
  AND token = 'XGMefwJ0lvVZGSwGnjjx2ZHhWaA6n4FrpynlKyUCcrU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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