SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f29483bdf500783da014241cd5ca7b25ffac39474e7eb140e2cce8e7216694ce' 
  AND token = 'hWX9HoDTGAtaVqKZcSVratlr1XE+CCj2pMA7SGgjC+c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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