SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c522895eafd20db649a975c3bbe313e32ec3a2ba148267082b3eaf07c1aa2d87' 
  AND token = 'EZbqDeaFmPejbpKv3pN043nkSubSmfdcwLvcA6LDhww=' 
  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"
    }
  }
}