SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c4188db853d7749313f8e37f263d3702b2d4b424011516343fed4e0fd476071' 
  AND token = 'cJL9J5yyI07LhLwpzhjJdFPJyJxfvF5AKdRVO2bre94=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}