SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9a1826d1c2c6b078e8667dc948fe79179de4266c9ab239ae2b5d6b6a948db58' 
  AND token = 'wLtLqT15a6mRL3pYLK/7OjjksRd8hWP7bbQIP6zxvAk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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